1. Technical Field
The disclosure relates to LED (light emitting diode) lamps for illumination purpose and, more particularly, relates to an improved LED lamp having a large illumination area.
2. Description of Related Art
An LED lamp is a type of solid-state lighting that utilizes LEDs as a source of illumination. An LED is a device for transferring electricity to light by using a theory that, if a current is made to flow in a forward direction through a junction region comprising two different semiconductors, electrons and holes are coupled at the junction region to generate a light beam. The LED has an advantage that it is resistant to shock, and has an almost eternal lifetime under a specific condition; thus, the LED lamp is intended to be a cost-effective yet high quality replacement for incandescent and fluorescent lamps.
Since LED lamps have many advantages; they are now used as street lamps, lawn lamps or home lamps for illumination purpose. Known implementations of an LED module in the LED lamp make use of a plurality of individual LEDs to generate light that is ample and of satisfactory spatial distribution. The large numbers of LEDs, however, increase price and power consumption of the module. Considerable heat is also generated, which, if not adequately addressed at additional expense, impacts the reliability of the LED lamp.
Further, since the LEDs are generally arranged on a printed circuit board having a flattened face, light emitted from the LEDs is concentrated on a small area confronting the LEDs due to high directivity of the LEDs, which is unsuitable for environments requiring an even and broad illumination. Thus, the LEDs mounted on the flattened face of the printed circuit board cannot have a large area of illumination.
What is needed, therefore, is an improved LED lamp which can overcome the above problems.